EPJ

Evolution of the projected area and associated perimeter of a uniformly dissolving particle

With the goal of understanding and modelling the reactive dissolution of solids, new microscopic methods have been developed for the investigations of the phenomena and kinetics of these reactions, and applied to the dissolution of uranium dioxide in nitric acid media.

The first paper presents a state of knowledge of the dissolution of uranium dioxide in nitric acid media. It highlights the numerous chemical and physico-chemical issues which still need to be addressed concerning its understanding, with a focus on autocatalysis, mass-transport and non-uniform attack of the solids.

Plastic scintillators consist in one or several fluorescent probes embedded in a polymer matrix. They are able to produce light while interacting with a radioactive source. Recently, their technology has been modified by making them denser to improve their absorption while limiting the fluorescence quenching, leading to make them usable as pseudo-gamma spectrometers.

This is just an example of the numerous advances reported in a review based on four editions of the ANIMMA conferences (www.animma.com). This review is organized according to the measurement methodologies: neutronic, photonic, thermal, acoustic and optical, and includes medical imaging as well as progress in data acquisition and electronic hardening. Applications involve many fields like fundamental physics, fission and fusion reactors, medical imaging, environmental protection and homeland security, radioactive wastes measurement and control.

In the general framework of transient coupled calculations, new developments of an accurate neutron kinetics model able to characterize spatial decoupling are described, together with an application to sodium fast reactors.